Abstract: In order to evaluate the influence of refining slag on inclusions in quantity,composition,size and morphology of spring steel,two different slag systems were designed to study the effect of slag basicity on total oxygen and inclusions by total oxygen analysis,slag sample analysis and inclusion analysis under EAF→LF→RH→CC process.The research shows that compared with low basicity slag (1.0),high basicity slag (1.7) has the advantage of deoxidization and desulfurization of molten steel,and the total oxygen is lower.The inclusions in steel are basically the same under different basicity conditions,which is mainly consist of MnS,CaO-SiO₂-Al₂O₃,Al₂O₃-MgO,CaS-MnS,TiS-MnS and other inclusions.The amount of MnS and CaO-SiO₂-Al₂O₃ inclusions in low basicity refining slag steel is significantly more than that in high basicity refining slag.The type A,B and D inclusions with high basicity slag are better controlled.Considering the inclusion control level,refining slag with basicity of 1.7 is more suitable.

Key words: spring steel, refining slag, basicity, inclusion